PERMANENT MAGNET AND PROCESS FOR PRODUCING THE SAME

摘要

One object of the present invention is to provide a method for manufacturing a permanent magnet which can effectively improving the magnetizing properties and coercive force with efficiently diffusing Dy into grain boundary phases without deteriorating a surface of sintered magnet of Nd—Fe—B family and does not require any subsequent working process. Sintered magnet S of Nd—Fe—B family and Dy are arranged in a processing chamber 20 apart from each other. Then Dy is evaporated by heating the processing chamber 20 under a reduced pressure condition to evaporate Dy with elevating the temperature of sintered magnet S to a predetermined temperature and to supply and deposit evaporated Dy atoms onto the surface of sintered magnet S. During which the supplying amount of Dy atoms onto the sintered magnet S is controlled so as to diffuse and homogeneously penetrate them into the grain boundary phases of sintered magnet before Dy layer is formed on the surface of sintered magnet.